Materials and training Questionnaires The participants will complete demographic information and fill in the trait and state version of the State-Trait Anxiety Inventory (STAI-t, STAI-s; Spielberger, 1983; Van der Ploeg et al., 1981) adapted to only report about the past week before the first session, and the trait and state version of the Attentional Control Scale (ACS; Derryberry & Reed, 2002). The STAI-t assesses trait anxiety (range 20-80), STAI-s assesses the participant's current state of anxiety, and the ACS assesses attentional inhibition, attentional shift, and the capacity to flexibly generate new thoughts (range 20-80). The internal consistency of these questionnaires is generally good. STAI- t, ACS-t and a demographic questionnaire will only be measured during the first session and during the last session (after the training). The STAI-s and ACS-s will be assessed on every session before the EEG measurement or training.